Abrasive belt



Aug. 23, 1949. I Q HARR|5 2,479,929

ABRASIVE BELT Filed March 19, 1949 INVEN TOR BY Owen H. Harris ATTORNEY Patented Aug. 23, 1949 UNITED STATES PATENT OFFICE ABRASIVE BELT Owen H. Harris, Milwaukee, Wis.

Application March 19, 1949, Serial No. 82,355

4 Claims. 1

This invention relates to an abrasive belt. More particularly, it relates to a new and improved abrasive belt so constructed that a greatly increased polishing or abrading surface can be obtained from an endless abrasive belt.

The art of making coated abrasives is well developed. A coated abrasive includes a backing of paper, cloth or a combination of both upon one or both sides of which there is adhered a surface of abrasive grits such as flint, garnet, corundum, emery, artificially fused aluminum oxide and silicon carbide. Various bonding materials have been suggested such as glue, polymerized rosin, synthetic resins such as phenol formaldehyde, polyvinyl alcohol, alkyds and the like. While the method of making coated abrasives is disclosed in numerous patents, a representative disclosure for making coated abrasives with a synthetic resinous binder is U. S. Patent No. 2,239,828.

Coated abrasive belts are generally formed by joining or splicing the free ends of a strip of coated abrasive material. Various types of joints or splices are known for joining or securing the ends together. Such joints or splices may be formed by abutting the ends, overlapping the ends, cutting the ends on a bias or diagonal, etc. and the ends may be bonded with a suitable bonding material such as glue or adhesive resin.

Many important industrial abrading and polishing jobs are done on abrading machines using endless abrasive belts. The length of time a belt will last before becoming worn or torn and needing to be replaced is often the determining factor in the performance of the machines. The time needed to replace worn or torn belts causes a shutdown of the machine. This replacement period is therefore an idle period during which abrading work time is lost. In addition many abrading machines require a considerable amount of space because of the length of the abrasive belt. By lengthening the length of the abrading belt, and thus increasing the length of time before shutting down for replacing the belt, the working time of the machine is increased. This, however, requires considerable more floor space as each installation will require more space.

Thus, there has been a demand for an improved abrasive belt which has an increased polishing or abrading surface which is provided by the device of the present invention.

Briefly, my invention comprises a coated abrasive belt in which an abrasive strip one end of which has been given a half twist before the ends are Joined.

Therefore, an object of my invention is to provide an endless abrasive belt with an increased polishing or abrading surface which can be economically constructed.

Another object of my invention is to provide an endless abrasive belt coated with abrasive material so constructed that the abrasive surface on both sides can be uniformly presented to a. work piece without changing the belt.

A further object is to provide an endless abrasive belt with a greatly increased polishing or abrading surface so that the space ordinarily required for abrading machines can be reduced by providing a shorter abrasive belt, but with an increased abrading surface area.

These and other objects and advantages will appear more fully in connection with the accompanying drawing in which:

Fig. 1 is a perspective view of the endless belt showing the half twist.

Fig. 2 is a longitudinal sectional view taken along the line 22 of Fig. 1.

Fig. 3 is a perspective view of the belt of Fi 1 positioned on a pair of pulleys.

Similar numerals refer to similar parts throughout the several views.

Referring especially to Fig. 2, it will be seen that one embodiment of my abrasive belt ill has a backing ll of paper, cloth or a combination of both to which is bonded by means of a binder I2 such as glue, but other bonds such as waterproof bonds and resinous bonds may be used, a supp y of coated abrasive material i3. The coated abrasive may consist of flint, garnet, corundum, emery, artificially fused aluminum oxide, silicon carbide and the like. If desired, an inorganic filler (not shown) such as calcium carbonate having a particle size of not more than microns may be included in the glue. As will be apparent from the drawings both sides of the backing II have been coated with the coated abrasives. In practice, it is preferred to coat one side of the backing through a conventional coated abrasive machine and then cure the coated strip by festooning before winding into rolls. The final cure can then be made by means of air drying, or other methods known to those skilled in the art. The roll of coated abrasive may then be rerun through the machine to coat the other side so as to provide a coated abrasive strip having both sides coated with abrasive material.

If desired the grits or abrasive material may be oriented, for example by means of an electrical field as described in the patents to Elmer C.

Schacht Nos. 2,027,307 and 2,027,309 dated January '7, 1936.

The cured coated abrasive material may then be cut into desired lengths. A strip of this coated abrasive material coated on both sides is then Joined or spliced it as shown in Fig. 1. While only one type of joint or splice l5, 1. e. a diagonal splice is shown, various other well known t are herein contemplated such as an abutting joint, overlapping Joint, interlocking joint. etc. It will be notedthat the belt iii contains a halt twist It, i. e. a 180 turn. as shown in Figs. 1 is. 3. This half twist it is formed by giving one end of the coated abrasive strip a half twist prior to Joining or splicing. It will thus become apparent, as shown in fig. 3 that the belt is is so constructed that it will reverse itself once every revolution so that the coated face of the belt is uniformly presented to the working piece. As the abrasive belt revolves around the pulleys ll, alternate sides of the belt are presented to the work piece on alternate revolutions of the belt.

' Thus, with my invention, I have succeeded in extending the life of an abrasive belt by presenting a greatly increased abrading surface without lengthening the belt. If desired, a belt of just one-half the length may be used in many installations requiring a specific abrading area since the abrading area is doubled without changing the belt.

While I have described an abrasive belt containing a half twist, it should be understood that other belts wherein it is desired to present alternate sides on alternate revolutions of the belt without changing it can be constructed in the manner described.

Many apparently widely different embodiments of this invention may be made without departing from the principle, breadth and spirit thereof, and it is to be understood therefore, that this invention is not limited to the specific embodiment thereof except as encompassed by the following cla.

I claim:

1. A coated abrasive belt comprising an abrasive strip One end of which has been given a 18W twist before joining.

2. A coated abrasive belt comprising an abrasive strip having an abrasive surface on the face thereof, one end of which has been given a twist before splicing to the other end.

3. An abrasive belt comprising a flexible abrasive strip having an abrasive surface on the face thereof, one end of which has been given a 180 twist before joining to the other end, said belt being adapted to provide a continuous abrasive surface when rotated.

4. An abrasive belt comprising a flexible abrasive strip having an abrasive surface on the face thereof, one end of which has been given a 180 twist before Joining to the other end. said belt being adapted to provide a continuous abrasive surface when rotated, and subjecting both sides of said belt to uniform wear.

OWEN H. HARRIS.

No references cited. 

